World’s Smallest LED Is a Single Molecule

By coaxing light out of a single polymer molecule, researchers have made the world’s tiniest light-emitting diode.

World’s Smallest LED is a Single Molecule

By coaxing light out of a single polymer molecule, researchers have made the world’s tiniest light-emitting diode.

This work is part of an interdisciplinary effort to make molecular scale electronic devices, which hold the potential for creating smaller but more powerful and energy-efficient computers. Guillaume Schull and his colleagues at the University of Strasbourg in France made the device with the conducting polymer polythiophene. They used a scanning tunneling microscope tip to locate and grab a single polythiophene molecule lying on a gold substrate. Then they pulled up the tip to suspend the molecule like a wire between the tip and the substrate.

The researchers report in the journalPhysical Review Letters that when they applied a voltage across the molecule, they were able to measure a nanoampere-scale current passing through it and to record light emitted from it.